Automatic circuit interrupter



Dec. 14 1926. 1,610,590

M. E. REAGAN AUTOMATIC CIRCUIT INTERRUPTER Y Filed March 24, 1921 W7 F1 f1 f /f r1 l ATTORNEY Patented Dec. 14, 1 926. l ,6 l

UNITEDSTATES PATENT OFFICE.

MAURICE E. REAGAN, OF PTTSBURGI'I, IENNSYL'VANIA, ASSIGNOR T0 WESTING- HOUSE ELECTRIC & BIAN'ECRING- CDMNY, 'CGBLFORATION OF PENNSYL- VANIA. f

AUTOMATC CIRCUIT INTERRETER.

Application filed March 24, 1321. Serial No. 454,994.

My invention relates to automatic reclosposition, to re-actuate it to its operative posi- 55 ing circuit interrupters and particularly to tion. The sectionalizing switch is thereupon interrupters of the type known, and einreclosed to reconnect the section to the cirployed, as sectionalizing switches. cuit.

One object of my invention is to provide Figure 1 of the accompanying drawings is means for disconnecting a faulty section of a diagrammatic view of a trolley feeder con- 60 a circuit embodying a plurality of sections ductor circuit, illustrating the division connected to a source of energy. thereof into a plurality of sections;

Another object of my invention is t-o pro- Fig. 2 is a schematic view illustrating the vide means, in a system of the above-indipotential gradients developed between the cated character, that shall operate to selecfault and sources of energy in the system de 65 tively disconnect a faulty section of the cirscribed in 1; and cuit in accordance with the potential grad- Fig. 3 is a diagrammatic view of a sectionient that is developed, upon the occurrence alizing switch illustrating the connection of 16 of a fault, between the source of energy and the elements thereof. f

the fault. A plurality of feeder conductor sections 4, 70

Another object of my invention is to pro- 5 and 6 are supplied with energy from two vide a system, of the above-indicated charsources of electromotive force 7 and 8. The acter, in which only the interrupters at the feeder conductor sections are adapted to suprespective ends ofthe faulty section shall be ply energy to corresponding sections of a opened, and the other interrupters are pertrolley conductor 9 through a plurality of 75 initted to remain closed. connecting conductors. The feeder con` A further object of my invention is to ductor sections are connected by means of provide a system, of the above-indicated sectionalizing switches 10.

character, in whch the faulty section shall Each sectionalizing switch 10 comprises a be immediately reconnectecl to the circuit main switch 11, an operating coil 12 and 80 upon the clearance of the fault. two auxiliary switches 13 and 14 that are In practicing my invention, I provide two closed when the main switch 11 is open. potential relays for each sectionalizing Two relays 15 and 1G are provided to control 80 switch, one relay being connected across the the circuit of the operating coil 12.

circuit on each side of the sectionalizing The relay 15 is connected between the sec- 85 switch. The closing mechanism of the section 4 and the return rail 17 through a tionalizing switch is controlled by these two resistor 18 relatively low resistance and relays and its energization is dependent upon a resistor 19 of relatively high resistance.

the energization of the potential relays to a The relay 15 comprises an operating coil 20,

predetermined degree sufficient to operate two main switches 21 and 22 that are open 90 th'e same. when the relay is cle-energized, an auxiliary Upon the occurrence of a fault, the potenswitch Q3 that is closed while the relay is detial available for energizing one yof the poenergized, and opened just after' the other tential relays decreases below a predetern switches 21 and 22 have closed.

mined value that is suflicient to maintain The relay 16 is similarly connected be- 05 that relay in its operative position. The tween the section 5 and the rail 17 through main switch is thereupon permitted to open a resistor 24 of relatively low resistance and and a resistor of relatively high resistance is the resistor 25 of relatively high resistance.

inserted between the source of energy and The relay 16 comprises an operating coil 2G the fault. Vifhcn the ratio of the resistance and two switches 27 and 28 that are open, 100 of the fault and the resistance of the resistor, when the relay is de-energized, and an auxilthat is connected across the terminals of the iary switch 29 that is closed, when the relay sectionalizing switch, attains a predeteris deenergized, and opened, when the relay mined value, the potential gradient between is energized, immediately after the closing the source of energy and the fault becomes of the switches 27 and 28. 105 so changed that sufficient voltage is im- A resistor 30 of relatively high resistance pressed across the potential relay, that has is connected between the feeder conductor meanwhile been actuated to its inoperative sections 4 and 5 in series with resistors 18 and 24; to prevent an exchange ot current ot relatively large value between the sections d and upon the occurrence ot fault in either section.

Assuming a normal operating voltage ot 60G volts, the relays 15 and 16 would be adjusted to operate, for example, at a potential of 200 volts. it conditions are normal throughout the system, normal potential will be impressed upon the operating coil 2O of the relay 15 from the feeder conductor a through the resistor 18, the switch la, and the switch 23 through the operating coil 2O to the rail 17. lt will be observed that the auxiliary switches le and 23 close-circuit the resistor 19 while the switches 1,0 and l5 are in their cle-energized positions. rEhe relay 15 is thereupon suiliciently energized to operate.

Upon the operation of the relai 15, the engagement ot' the switches 21 controlled thereby, the auxiliary switcn 28 is opened. rlhe design and construction olf the relays 15 and 16 are such that a lower value of current suilices to maintain the relays in their energized position than is required to actuate theni to that position. Thus, alter the operation ot the relay 15, the opening ot the switch 23 per nits the insertion ot the resistor 19 into the circuit oit the operating coil 20.

Assuming conditions on the section conductor 5 also to be normal, the relay 16 is similarly actuated to its energized position to close the switches 27 and 28 and to open the switch 29.

Both relays l5 and 16 being in their energized positions, the operating coil 12 oli the switch becomes energized through the switches 21, 22 and 28 of the relays 15 and 16, to close the main switch 11 and to open the auxiliary switches 13 and 1li- The switch 11 will now remain closed so long as both the relays 15 and 16 remain in their energized positions.

Upon the occurrence ot a fault in a portion ot the system connected to the section conductor 5, the potential gradient ot the system becomes such as is illustrated in Fig. 2 and the voltage available tor energizing the potential relays associated with the sectionalizing switches on either end of the `section 5 becomes less than the value of the voltage required to maintain the relays in their operative positions.

Referring to the sectionalizing switch 1() that is connected between the sections and 5, it will be observed that, upon the occurrence of a fault, as indicated at the point A oit the section conductor 5, the potential difference available between the conductor 5 and the rail 17 is less than the predetermined voltage of 200 volts that is necessary to maintain the relay 1G in its energized position. The relay 16, therefore, permits its alter l 22 switches and 28 to open and the auxiliary switch 29 to close.

The opening oi the switch 28 opens the circuit or the operating coil 12 ot the switch 10, whereupon the main switch 1l is opened. The opening of the switch 11 permits the resistor SO to become eillective between the sections 5 to limit the value ot current that may traverse those sections to t-he Ylia-ult at the point Since the voltage of the section conductor l is still normal, the relay 15 remains in its energized position.

the resistance o' the fault the ooint A increa es, the potential gradient changes in accordance with the dotted curve in Fig. 2 and the relay 15 comes within a zone ot the potential gradient that vprovides a potential dit rence which is suiiicient to energize the relay to eti'cct switches 2"? and 28.

una

stance ot the fault and the reresistor 8O attains a predethe relay 1G becoines'snthg d to be actuated to its operative position. rl`hat is, when the resistance or the iault so increases that the voltage of the circuit is dis buted between the resistor 30 and the resistance olf the fault in a predetermined ratio, the relay 16 will ref close.

The reclosing ot the switches 27 and 28 again completes the energizing circuit ot Vthe operating coil 12 o' the sectional-izing switch 1f@ and the main switch 11 is reclosed to reconnect the sections d and 5.

lt will thus be observed that the operation ot the system embodying my invention is dependent upon the potential gradient that is produced upon the occurrence oil a fault between the 'fault and the source ot' energy, and that the selective operation ci the rclays in accordance with the potential gradi- .it permits the disconnection of only the faulty section.

My invention is not limited to the speciiic elements that are illustrated nor to thespecilic rrangeinents of those elements, since inodiiications may be made therein within the spirit and scope of the invent-ion, as set tween the r sistance ot termine-d v cientiy enero'WV forth in the appended claims.

cla' s my in tion 1. ri. "tric circuit se"tioiializing system coin irisin. two circuit sections land a comcircuit interrupt-er '1 sections, a rel tion to the the traversal C) mon return conductor, a

etween two inoit-limiting reurn conductor and cooper: controlled by the relay devices i i Lendering the portion oic the current-limiting resistor between said intermediate points ineffective and for controlling)` the operation ot' the circuit interrupter. 2. An electric circuit sectionalizing` system comprising two circuit sections and a common return conductor, a circuit interrupter connected between the circuit sections, a resister connected in parallel relation to the circuit interrupter tor limitingl the traversal of current between the circuit sections when the circuit interrnpter is open, two relay devices respectively connected between two intermediate points ot' the current-limiting resistor rind the common return conductor, a resistor connected in series with each or" the relay devices, and a circuit cooperatively controlled by the circuit interrupter and the associated relay device for controlling' the etectiveness ot each or said series-connected resistors. l

3. An electric circuit sectionalizing system con'iprising` two circuit sections and a common return conductor, a circuit interrupter connected between the circuit sections, a resister connected in parallel relation to the circuit interruptor Afor limiting` the traversal ot current between the circuit sections when the circuit interrupter is open, two relay devices respectively connected between two intermediate points of the current-limiting re sistor and the common return conductor, a resistor connected in series with each of the relay devices, and a circuit connected in parallel relation to each of said series-connected resistors and comprising an auxiliary switch ctuated by the circuit interrupter and a switch actuated by the associated relay device whereby each or said series-connected resistors is short-circuited when the circuit intcrrupter is open and the associated relay device is energized below a predetermined degree.

In testimony whereof', I have hereunto subscribed my namethis 18th day of March 1921.

MAURICE E. REAGAN. 

